[billvalt]

I have installed new expensive vinyl plank flooring. Lately the floor underneath at a joint has bucked up making a hump under the flooring in a three foot area where you walk. The floor had new joists replaced and looking underneath the area where the buckling is the joist had not been replaced. The screws evidently are releasing from the brittle, formerly termite damaged old joist causing the flooring under the vinyl flooring to buckle. Is there any way that I can pull the floor down from under the house instead of tearing out all the flooring in the house? This is a one story house with about a three foot crawl space. There is a sub-floor with Advantech 3/4 inch on top of that then the vinyl plank flooring. Any ideas.

 

[mako1]

What is the sub floor material and how thick is it?

 

[billvalt]

Sub floor is also plywood 1/2 - 3/4.

 

[Bud9051]

Hi Bill and welcome to the forum.
Yes, the floor can be pulled down, but my concern would be why dit it decide to buckle? And, is it the subfloor or the advantec? Even if the subfloor has pulled away from the joists it would be difficult for it to move the advantec.

I'm thinking there is a moisture issue affecting the floor and now with the new vinyl above it may not be drying as it was. Does your crawlspace have a dirt floor? Do you have a relative humidity meter to check the moisture level down there? You will also want the temperature at the same place and time.

Bud

 

[mako1]

My thoughts also.It would be very odd for the Advantech and the subfloor to buckle.Especially if the Advantech was properly attached to the subfloor and 3/4" thick.

 

[billvalt]

There has been a moisture problem in the past. A new vapor barrier has been put in. The screws that are holding down the advantech are pulling out of the rotten joist. I can sister in new floor joist that was not replaced but it is in a hard area with duct work around it. I think that's why the workers did not replace this particular joist.

 

[billvalt]

The buckling is along a line where the advantech meets the other piece of older flooring. The advantech was screwed down but not glued down. it is just at the joint on the top layer where it is coming up. The sub floor is not coming up but just the advantech top plywood at the joint.

 

[mako1]

Where is the vapor barrier?The Advantech should have been screwed to the subfloor but not the joist. The joints on the subfloor should not be in line with the Advantech.

 

[Bud9051]

If your finished floor had never been installed that advantec should still be right where it was when installed. Something has changed and I suspect it is humidity aka the moisture level. 4x8 sheets of sheathing will often be installed with a 1/8th gap to avoid buckling during the building process when exposed to unexpected rains. Your advantec was probably tongue and grove and they drove it together tight.

Still need those moisture readings, especially since you have already had a moisture issue.

As for pulling the floor down, tricky, since it is the advantec. If you and whoever else is at home stand on the problem spot, does it go down? If not, that is the first requirement. You are not going to pull it down if 300 or 400 pounds on top of it doesn't move it. Put a level across it and step on the bulge to see if the level drops to flat.

Bud

 

[joecaption]

Subfloor "1/2"- 3/4" makes no since. it's one or the other.
Vapor barrier needed to be on the ground and should have been at least 6 mil.
No nail or screw is going to hold in a termite eaten joist.
There just is no way to pull down a subfloor or underlayment from under the floor.
Pictures from under the floor would be nice.

 

[carpdad]

It is within the imagination to remove some of the underlayment with a dremel or such but there are parts that you can't get, such as parts over the joists. More than likely, the ply underlayment was laid without space and buckle is coming from expansion problem. Screwing into a rotten joist began it all. It is not a repair that can be done from below. There is noway you can pull the buckled underlayment from below without damaging thin vinyl flooring, or match the seam again. Building materials are not that pliable. Buy a syringe and squirt some acetone under the vinyl. If that loosens the glue, you may be able to pull up the flooring without a lot of damage. If you can still get same brand vinyl floor, repair is that much easier.